Turbo Towers

Like the turbocharged cars it supported, Saab's 'Inca' was one of the most distinctive designs on the road

Feature Article from Hemmings Motor News

Saab automobiles have always taken the road less traveled. From technology to design, their "different-ness" has always been for a carefully engineered reason, and they rarely have let form override function. Every now and again, though, the automaker has let slip a bit of fancy and flash, and what better way could they celebrate the introduction of their 1978 99 Turbo--and its direct successor, the 1979-1980 900 Turbo--than by splashing out on a wild wheel design like the "Inca."
Bringing modern turbocharging (coupled with electronic fuel injection) technology to the mass-produced automobile was the brief of the iconic 99 Turbo, and setting it apart from its lesser siblings were its front and rear spoilers and special wheels. Sized at 15 x 5.5 inches, these silver-painted aluminum alloy wheels weighed in at a relatively light 15.5 pounds each, and their four-lug pattern used 108mm spacing and a 64mm center bore that was capped with an octagonal black plastic cap with the SAAB logotype decal in the center. Each Inca wheel sported 12 ventilation holes punched in four groups of three, each hole in an inward step towards the rim. The Saab logotype, the wheel dimensions and part numbers were also cast in raised relief onto the wheel itself.
First seen on the 99 Turbo that debuted at the 1977 Frankfurt Motor Show in Germany, this design was intended to echo the angled vanes of a turbocharger's compressor/turbine wheel. And as it was named, the Inca's design also recalled the tiered/stepped architecture that the Inca people found necessary for agriculture in their mountainous regions, as well a popular motif seen in Inca jewelry patterns. The Inca wheel fits all 99s, as well as the 1979-1987 900s, and because they have not been reproduced, nice original or restored versions are highly sought.
Because they were used for three years and in two series of Turbo cars, Saab Inca wheels came to represent the automaker's distinctive high-performance line, and their influence remains strong 30 years later. After the 900 Turbo with Special Performance Group (SPG) option--and its aerodynamic flat three-spoke alloys--became popular in the mid-1980s, the company designed a new 15 x 5.5-inch accessory wheel that combined both the Inca and SPG designs into one, called the "Super Inca." Made in Italy by Cromodora, this wheel featured two ridges that echoed the angular steps of the original Incas, that filled the hollows between the three flat spokes; the Super Inca was also made in 15 x 6-inch, 1988-and-newer bolt pattern for "classic" 900s and 9000s. A further development of the original Turbo wheel theme is the new "Inca," a heritage-inspired five-lug, 18 x 7.5-inch double three-spoke wheel with stepped inner layers that made its debut as a 2008 accessory for European 9-3 models, proving once again that distinctive design never goes out of style.

This article originally appeared in the October, 2009 issue of Hemmings Motor News.